Blind-stitching attachment for sewing machines



Nov. 8, 1938. 2,136,164

P. EOGUHN BLIND STITCHING ATTACHMENT FOR SEWING MACHINES 2 Sheets-Sheet 1 Filed June 9, 1937 FIG. 2

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gwuwrm, Pay/Z flo whn/ @Wocweu/ Patented Nov. 8, 1938 BLIND-STITCHING ATTACHIVEENT FOR SEW- ING MACHINES Paul Boguhn, Berlin-Spanish; Germany, assignor to The Singer Manufacturing: Company, Elizabeth, N. J., a corporationoi? New Jersey Application June 9, 1937, Serial No. 147,165 In Austria March 31, I937 Claims.

This invention relates to blind-stitching attachments for sewing machines of the type comprising a work-guide over and under which the work is folded for presentation to the machine needle, and a cooperating yielding abutment, and has for an object to provide a simple and compact construction in which the abutment is positively actuated in dependence on the movement of the sewing machine feed-dog whereby to relieve or to discontinue pressure of the abutment against the work during the feeding stroke. A further object is to ensure exact guidance and adjustment of the work under conditions which will avoid undue wear of the parts of the attachment.

According to the invention the abutment is operatively connected with a lever presenting an inclined portion cooperative with a stationary face that may be presented by a slot or opening in the throat-plate penetrated by said inclined portion.

In a preferred embodiment of the invention, the carrier for the abutment is detachably secured to the sewing machine presser bar and includes a part formed as a presser foot. The lever is pivoted to the carrier and is fitted with an adjustable slide presenting a pivot pin on which is mounted a guide plate passing through a slot in the carrier. The abutment passes through slots in the guide plate, being guided also by a pin uprising from the guide plate. A guide frame or work-guide proper presenting an edge-portion over and under which the work is folded is hingedly connected to a yoke fixed in relation to the bed-plate and is adjustable by manipulation of an adjusting screw engaging the hinge pin. The guide frame is subject to the action of a spring tending to lift said guide frame away from the machine bed-plate whereby introduction of the work is facilitated.

In the accompanying drawings which illustrate by way of example an embodiment of the invention, Fig. 1 is a part side elevation part vertical section of the attachment, Fig. 2 is a plan, Figs. 3 and 4 are fragmentary views showing the parts in two different positions of the abutment. Fig. 5 is a fragmentary view showing two superposed and folded fabric plies secured to one another by a blind seam. Fig. 6 shows the fabric plies unfolded.

The device shown comprises a guide frame 3 or guide proper having an aperture 2 bounded by an edge-portion I over and under which the fabric plies a, b to be blindstitched are folded as indicated in dotted lines in Fig. l, and in full lines in Fig. 4. The guide frame 3 is carried by a bracket 4 to which it is connected by screws 5 passing through elongated holes in said lugs HI, H of the yoke I2.

The guide frame 3 is provided adjacent to the pin 1 with a downturned lug l6 having an aperture penetrated by a headed screw l5 secured to said lug by means of nuts I! and threaded into an internally threaded transverse orifice in the pin I. As the screw [5 is held by the nuts I! against displacement in axial direction relatively to the lug 16, by rotation of the screw Hi, there is effected longitudinal shift of the guide frame 3 relatively to the base member l3. As the base member 13 is fitted to the machine bed in substitution for the usual cover slide plate and is anchored by the plate IB and screws l9 to the machine bed-plate, there is thus rendered possible displacement of the guide frame 3 relatively to the machine needle, whereby there may be effected fine adjustment, such as is rquired for different thicknesses of the work. Between the guide frame 3 and the base member I3 there is interposed adjacent to the pin 1 a spring which tends continuously to lift the guide frame 3 away from the base member '3, thereby facilitating introduction of the work.

The carrier for the abutment cooperating with the guide frame is secured to the machine presser bar 5|] of the sewing machine, for ex ample, by means of a clamping screw 5!.

the embodiment illustrated, the carrier 2| has a part 22 formed as a presser foot having a sole portion disposed above the feed-dog 53.

oted to the carrier 2| by means of a shouldered screw 23 secured by a nut 24 is an actuating lever 25 having at its lower end an inclined depending tail or guide portion 26 which penetrates a slot 21 in the throat-plate 28 and is guided thereby.

gated slot 33 in the slide.

Pivoted on the pin (ill 30 is a guide plate 34 which is secured against withdrawal from the pin 30 by a cotter 31. This guide plate 34 has at its free end a tongue 35 which passes through a slot 36 in the lower end of the carrier 2| directly above the sole portion of the presser foot 22 so as to be supported by the latter. A stop 38 fitted to the end of the tongue 35 limits the movement of the tongue 35 in the slot 36.

In the rocking movement of the lever 25 about the pivot 23, the guide-plate 34 is shifted relatively to the carrier 2| and to the presser foot 22. Secured to the guide-plate 34 is an upright pin 39. The guide-plate 34 is further provided with a slot 40 for the passage of the needle 54, and with slots 4|, 42 penetrated by depending prongs 44 of the abutment plate. The abutment plate is subject to the downward pressure of a spring 45 abutting at its lower end on a lug 43 of said plate and at its upper end against a cotter 46 fitted to the pin 33. Slots 41 and 48 in the guide-plate 34 serve for guiding the thread. A slot 49 in the abutment plate presents a free passage for the vibratory needle 54 in case the fabric is not to be pierced during the vibration of the needle.

With the described construction and arrangement of the parts the abutment is continuously urged towards the throat-plate 28, and during the blind stitching operation the fabric plies to be blind-stitched and folded around the edgeportion 1 are pressed by means of the presser foot 22 towards the throat-plate 28 or the feeddog 53. Accordingly, when the carrier 2| is ,7 pushed away from the throat-plate 28 together with the Work by the rising movement of the fecd-dog 53 through the usual feed slots in the throat-plate 28, and when the carrier 2| is again. lowered towards the throat-plate on the descent of the feed-dog, the abutment is displaced laterally during such vertical movement by the action of the inclined tail portion 26 of the lever 25 guided in the slot 21 of the throat-plate. The inclination of the tail portion 26 of the lever 25 is such that, in the ascent of the carrier 2|, the abutment is moved laterally in the direction away from the needle, and, in the descent of the carrier, is again moved towards the needle. In this way, there are effected the necessary movements for relieving or discontinuing the pressure on the work during the feeding stroke.

I claim:-

1. In a sewing machine having stitch-forming mechanism including a needle and feeding mechanism including a feed-dog, the combination with a work-guide over and under which the work is folded for presentation to said needle, of a yielding abutment co-operative with said workguide, a vertically movable carrier for said abutment, said carrier having a part adapted to be lifted by said feed-dog, and a lever operatively connected with said carrier, said lever having an. inclined part functioning as a wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

2. In a sewing machine having stitch-forming mechanism including a needle and feeding mechanism including a feed-dog, and a slotted throatplate above said feed-dog, the combination with a work-guide over and under which the work is folded for presentation to said needle, of a yielding abutment co-operative with said work-guide, a vertically movable carrier for said abutment, said carrier having a part adapted to be lifted by said feed-dog, and a lever operatively connected with said carrier, said lever having an inclined depending part penetrating a slot in said throat-plate and functioning as a wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

3. In a sewing machine having stitch-forming mechanism including a needle and feeding mechanism including a feed-dog, and a Dresser-bar, the combination with a work-guide over and under which the work is folded for presentation to said needle, of a yielding abutment cooperative with said work-guide, a vertically movable carrier for said abutment, said carrier being attached to said presser bar and having a part adapted to be lifted by said feed-dog, and a lever operatively connected with said carrier, said lever having an inclined part functioning as a wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

4. In a sewing machine having stitch-forming mechanism including a needle and feeding mechanism including a feed-dog, the combination with a work-guide over and under which the work is folded for presentation to said needle, of a yielding abutment co-operative with said work-guide, a vertically movable carrier for said abutment, said carrier having a part formed as a presser-foot and adapted to be lifted by said feed-dog, and a lever operatively connected with said carrier. said lever having an inclined part functioning as a wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

5. In a sewing machine having stitch-forming mechanism including a needle and feeding mechanism including a feed dog, the combination with a work-guide over and under which the work is folded for presentation to said needle, of a yielding abutment cooperative with said work-guide, a vertically movable carrier for said abutment, said carrier having a part adapted to be lifted by said feed-dog, and a lever pivotally connected to said carrier, said lever having an inclined part functioning as a Wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

6. In a sewing machine having stitch-forming mechanism including a needle and feeding mechanism including a feed-dog, the combination with a work-guide over and under which the work is folded for presentation to said needle, of a yielding abutment cooperative with said work-guide, a vertically movable carrier for said abutment, said carrier having a part adapted to be lifted by said feed-dog, a lever operatively connected with said carrier, a guide-plate supported by said lever and sustaining said abutment, said lever having an inclined part functioning as a wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

7. In a sewing machine having stitch-forming mechanism including a needle and feeding mechanism including a feed-dog, the combination with a work-guide over and under which the work is folded for presentation to said needle, of a yielding abutment co-operative with said workgulde, a vertically movable carrier for said abutment, said carrier formed with a slot and having a part adapted to be lifted by said feed-dog, a lever operatively connected with said carrier, a slide adjustably supported by said lever, a pivot on said slide, and a guide-plate mounted on said pivot, said guide-plate passing through the slot in said carrier and sustaining said abutment, said lever having an inclined part functioning as a wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

8. In a sewing machine having stitch-forming mechanism including a needle and feeding mechanism including a feed-dog, the combination with a Work-guide over and under which the work is folded for presentation to said needle, of a yielding abutment cc-operative with said workguide, a vertically movable carrier for said abutment, said carrier having a part adapted to be lifted by said feed-dog, a lever operatively connected with said carrier, a slide adjustably supported by said lever, a pivot on said slide, and a guide-plate on said pivot, said guide-plate formed with slots and sustaining said yielding abutment, said abutment penetrating the slots in said guide-plate, said lever having an inclined part functioning as a wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

9. In a sewing machine having stitch-forming mechanism including a vibratory needle and feeding mechanism including a feed-dog, the combination with a Work-guide comprising a base member, a guide proper, over and under which the work is folded for presentation to said needie, a hinge pin connecting said guide proper to said base member, and a screw penetrating said guide proper and threaded into said hinge pin for effecting adjustment of said guide proper relatively to said base member, of a yielding abutment co-operative with said work-guide, a vertically movable carrier for said abutment, said carrier having a part adapted to be lifted by said feed-dog, and a lever operatively connected with said carrier, said lever having an inclined part functioning as a wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

10. In a sewing machine having stitch-forming mechanism including a vibratory needle and feeding mechanism including a feed-dog, the combination with a work-guide comprising a base member, a guide proper hinged to said base memher, over and under which guide proper the work is folded for presentation to said needle, and a spring urging said guide proper away from said base member, of a yielding abutment co-operatve with said work-guide, a vertically movable carrier for said abutment, said carrier having a part adapted to be lifted by said feed-dog, and a lever operatively connected with said carrier, said lever having an inclined part functioning as a wedge to impart lateral movement to said abutment in the lifting movement of said carrier.

PAUL BOGUHN. 

